Methods for introducing electrical insulations in different regions of a printed circuit board, which are known as scribing methods, for producing electrically insulated conductor tracks, for example in the production of printed circuit boards, are already known from DE 10 2004 006 414 B4, in which for the partial removal of defined regions, these regions are heated selectively by laser radiation in order to reduce the adhesion, and are then removed as a whole. In order to confine the heating to the defined regions, a thermal insulation is initially produced by the laser beam around the perimeter of these regions by using the laser beam to introduce a linear recess.
DE 44 29 522 A1 already teaches a method for introducing electrical insulations in a printed circuit board by introducing a recess between different regions of an electrically conductive layer on a substrate, wherein the groove-shaped recess is introduced selectively in the conductive layer along a machining path by means of thermal energy input from a laser beam. In this case, the end portions of the same recess or different recesses are joined to one another, said end portions of one recess or different recesses being introduced in overlapping parallel lines in order to insulate different regions.
DE 32 45 272 A1 relates to a method for producing miniaturised track geometries arranged on a substrate and lying at least in one plane. In this case, the burn marks produced by a programmed laser in the layer introduced of conductive material and covering the full surface of a substrate are controlled so as to produce inductance.
U.S. Pat. No. 5,525,205 A already describes a method for partial detachment of a defined region of a conductive layer, in particular a copper layer, by means of a laser beam, in which the laser-beam parameters are set such that only the conductive layer is removed, without an underlying substrate that supports the conductive layer also being affected at the same time, wherein said region is insulated from the adjoining regions of the conductive layer by removing the conductive layer in the outer edge region of said region. The enclosed region of the conductive layer is then removed by chemical etching.
U.S. Pat. No. 6,662,439 B1 already discloses a method for laser ablation of a metallic layer from a flexible substrate material in the continuous feed process. The substrate material is a polymer, for example polyester, which supports a thin metallic layer, for example introduced of gold, which is selectively removed by an Excimer laser.
In addition, U.S. Pat. No. 5,759,416 A relates to a method for laser ablation of a thin metallic layer from a non-metallic substrate material. The metallic layer is gold, for example. A focused laser beam travelling along a pre-programmed path is used for the ablation of the metallic layer.
A method for laser removal of conductive layers by reducing the adhesion between conductive layer and substrate is known from EP 0 834 191 B1. Similar methods are also known from US 2003/0047280 A1 and JP 2003047841 A.